Pull gun



Jan. 21, 1958 G. J. VAN HYECKE 2,820,566

I PULL GUN Filed Feb. 3, 1956 2 Sheets-Sheet 1 INVENTOR. 56072 62 J" 1 42? W ek's BY v I raw/wry;

1958 G. J. VAN HECKE ,820,

PULL GUN 2 Shets-Sheet 2 Filed Feb. 3, 19

'PULL GUN United. states Parent George E. Van Hecke, Detrit,Mich., assignor to l-luck Manufacturing Company, Detroit, Mich., a corporation of Michigan Application February 3,1956, .serialzNo. 363,284

18 Claims. (Cl. 218-47) means.

Another object of the inventi'on-is'to provide an improved pull gun incorporating improved means :forredueing the clearance requirements between the end of'the gun and the longitudinal axis ofablindrivet .or the-like during the drivingthereof.

.Another object of the'inventionis to provide an improvd. pull gun that is econo'mical'to manufacture and assemble, durable, efiicient and reliable in operation.

'Another object-of'the invention is to provide -animproved fluid-actuated pull jgun incorporating improved control means which facilitates the successive actuation of the driving *cornponentsas .a function of predetermined driving forces.

Still another object of the inventionlis to provide an improved fiuid-actuatedpull gun which iscompact and relatively lightin weight, which maybe operated efficiently with a minimum of clearancelinrelatively close quarters, and which reduces the labor a'nd expense of drivingblindrivets and the like.

The above as well as other-objects and advantages of the present invention will'hecome apparentfrom thefollowing description, the appended claims and the accompanying drawings wherein:

Figure i1 .is a longitudinal sectional 'view'ofa fluidactuated .pull gun 'e'mbodyingthe "present invention;

Fig. 'Z'is atopplan'view oftheptillgun illustratedin Figure 1;

Fig. '3is atransverse sectionalviewof 'thepull -gun"illnstrated in Fi'gure Lteikenon the-line 33-'thereof;

Fig. 4 isa'sectionalview of the pull gun-illustrated in Figure 1, taken on-the line 4-4 theredf;

Figs. and 5B are longitudinal sCtiodal'vieWsofa i'blind'rivet before and after the "driving operation; and

Figs. 6,' 7, 8and9 are diagrammatic longitudinali's'ectiona'l views showing successive steps "in a rivet' setting operation I utilizing the pull gun -embodying the I present invention.

Referring ito the drawings, the present invention :is

:shown incorporated in "a fluid actuated :pull tygun, .-gen erally designated. 5, which 'is of the double-"acting Itype andwhichiis, particularly adapted-for .use in driving conventional conical .keystonerlocking typeblind rivets, although it will he-understood that the present'invention is applicable to other uses. The pull gun '5. .includes a a pneumaticpiston "assembly 8. Thehousing fi alsoi-n- "clu'des an integral neck portion 9, are an' hydraulic drivi'ng head assembly 10 ismOu nted-on the end of theneck pnrtion' fl remote zfro'math'e icylinde'ri 7. 'Thei'neck portion ilserves asia hand grip and also carriesza'nielongate'icylin- 2,82%,5iifi Patented Jan. 21, 3358 ice 2 der II in which an "hydraulic ra'rn assembly 12 is =reciprocally mounted. The cylinder 1-1 is filled with hydraulic flu id, and thhe hydraulic ram assembly 'serves to transmit fluid pressure imposed on the piston assembly sto'thedriving head assembly 10.

For-the purpose 'of'controllingthe piston assenibly's, a trigger 14 is provided WhlCh'lS pivotallyconnect'ed to the neck portion 9 of theho'using at a position adjacent the head 10. The trigger 14'is operativelyconnected to 'a'valve 20 through the agency of a spring 16 and'an actuating lever 18, and the valve 201s sli'dably mounted in the bore'21 of a valve housing ZZ-fixed to the housing 6.

The "valve housing 22 'is provided with an inlet 31 which is connected by a'supply line 32-to a source of'air under'pressure,'while the bore 21 ofthe valve housing communicates with the head and'rod ends of the-cylinder 7 through ports 30 and 34, respectively.

-As shown in Fig. l, the diameter of the left end portion of the valve 20 is substantially greater than the diameter'of-the right end portion'thereof. Because of'the ditferencesin the cross sectional areas "of the opposite end=portions of the valve, the valve tends itosmove to theleft when air is admitted'under pressure inzthe bore .21. Consequently, the valve'moves tothe: position shown :inFig. -1 whenever the trigger lliis released.

The piston assemblyS-includes a piston :24 which'is .mounted .for reciprocation in the cylinder :7, and :the piston-:24is connected by'means of'adrive tuhe z-toa piston 28 mounted for reciprocation in the cylinder *11. With such a COl'lSlIl'llCtlOIlyV/ll6l1fi16 trigger 14 is'sq'ueezed, it acts through the spring 16 and the lever 18 to move the valve'29to the right, as viewed in Figure 'l,'to connect the head end of the cylinder 7 to the-sourceof air ,pressure through the "port "3h,-the bore zlof-the-valve housing 22 and the supply line 32. 'At thesameitirnefthe rod end ofthe cylinder 7 is connectedto atmosphere i-lhIGHgh'thE-POI'i 34. This action-admits the air-under pressure into the=head end of the cylinder 71 and relieves the-pressure in the rod end of-the-cylinder'-7,1with the resultthatthe piston 24 and the piston 28 are-driven forwardly and apply pressure to the hydraulic fluid-in sthe cylinder 11.

The .driving head 10 of the gun includes a-colletor -gripping. jaw members 40 which serve-to grip and pulla .rivet .pin during the driving thereof. The collet members 40 are mounted'in one end of a tubularactuating'shaft 42,'the\opposite endof which threadably'engages a piston rod 44. In accordance with the presenhinvention, the lplStOH-I'Od 44lSfiS6Clll6d to a piston 46 mounted for reciprocation in a cylinder 48, the longitudinal axis of the piston-rod 44 beingoffset with respectto the longitudinal housing '5 which defines a cylinder 7"in which ism-ounted axes of the. piston 46 and the cylinder 48-towardthe end 4 of the. gun. With such a constructiomthe distance between the end 49 of the gun and the longitudinal axis of thepiston roddd isreduced, thereby facilitatingthe use ofthe gun in relatively inaccessible locationsiwhere clearance requirements for the gun are critical.

Thrust-bushing members 50 and 52 are fittedover the 'j-pistonrodand the member 42 and support an inn'er anvil 54: inz a fixechposition relative tothe drivinghead 10. An "iouter anvil-56 is provided which is mounted :coaxially .with'respect to the inner anvil 54 andwhich is supported -.upon a tubular member 58 that extends into-asecondary cylinder 62 provided within the head 10, the tubular member 58 being retained by an integral flangectl. The tubular-member 58 bears against a secondarypistom 64 :that; is mounted for reciprocation in theseeondarys cylinder 62, the fluid pressure applied to the secondarypistonfid being. controlled, 7 as will be explained in greater detail,

to maintain-the outer anvil'56 in an advanced position beyond the inner anvil 54 until a predetermined pulling 7 force is exerted on the rivet being driven.

The secondary cylinder 62 is filled with hydraulic fluid and is provided with a port 66 leading through a springbiased valve 68 and a port 72 to a secondary reservoir 70. In addition, the secondary reservoir 70 is connected to the secondary cylinder 62 by a passageway 79 leading through a check valve 74 to an inlet port 76 in the secondary cylinder 62. The secondary reservoir 70 is substantially cylindrical in the embodiment of the invention illustrated and is provided with a freely slidable piston 78. An air supply line 100 is also provided which communicates with the upper end of the main hydraulic cylinder 48, and the upper end of the cylinder 48 communicates with the upper end of the reservoir 70 through a port 101.

The pull gun may be operated to drive a blind rivetassembly, generally designated 80, of the conical keystone lock type. As shown in Figs. A and 5B, rivets of the type illustrated include a pin 81 and a collar 82, the pin having an enlarged head portion 83 and a shank portion 84 while the collar includes a sleeve portion 85, a flange portion 86 and a frangible locking portion 87. The rivet assembly is initially inserted into aligned apertures 88 provided in the workpieces 89 and 90 which are to be fastened together. The gripping jaws of the collet 40 are then fitted over the pin 31 of the rivet assembly and the outer anvil 56 is pressed against the flange 86 of the rivet collar. The trigger 14 is then squeezed so as to move the valve 20 in the bore 21 of the valve housing 22 to open the port 30 to admit compressed air to the head end of the cylinder 7. At the same time, the port 34 is opened to atmosphere. The compressed air thus drives the piston 24 forwardly, and the piston 24 acts upon the ram piston 28 through the agency of the driving tube 26 to drive the hydraulic fluid in the ram cylinder 11 through the port 92 into the hydraulic cylinder 48. The hydraulic fluid thus forces the piston 46, together with the piston rod 44, upwardly, as viewed in Figure 1. rod 44 then draws the collet actuating member 42 upwardly so that the collet 40 grips the rivet pin and pulls the rivet pin through the rivet collar. The reaction against the pulling force on the rivet pin 81 is borne by the outer anvil 56 which bears against the flange 86 of the collar. As the head 83 of therivet pin is drawn against the sleeve portion 85 of the collar, the shank 84 of the rivet pin expands the sleeve portion 85 of the collar to fill the apertures 88 in the workpieces 89 and 90 and the end of the sleeve portion 85 adjacent the head 83 of the pin is upset to form the blind head 91 of the rivet. At this point, the piston rod meets with substantially increased pulling resistance, and the pressure of the hydraulic fluid within the cylinder 48 increases sufliciently to move the valve 68 against its biasing spring 71. This movement of the valve 68 opens the port 66 so that hydraulic fluid trapped within the secondary cylinder 62 can pass into the secondary reservoir 70. This permits the outer anvil 56 to retract in response to the reaction force against the pulling of the rivet pin and brings the inner anvil 54 into engagement with the collar of the rivet assembly. The inner anvil 54 bears against the frangible portion 87 provided on the rivet collar, and further movement of the piston 46 causes the inner anvil 54 to sever the franjgible portion 87 from the collar and drive the severed portion between the collar and the pin to form the keystone lock, as will be appreciated by those skilled in the art. After the keystone lock has been completed, additional movement of the piston 46 breaks off the rivet pin at its break point 95. The broken-0E end of the rivet pin is then ejected through the hollow piston rod 44 and a tube 49 which extends from the upper end of the piston rod and is slidably sealed through the head 98 of the hydraulic cylinder 48. p

The trigger 14 is thereupon released and the control valve 20 is returned to its initial position because of the The piston 1 4 differences in the cross sectional areas of the opposite end portions of the valve, as previously described. Movement of the control valve 20 to its initial position opens the port 30 to atmosphere and connects the port 34 to the source of air pressure so as to retract'the piston 24. The rod end of the cylinder 7 is connected by the air tube 100 and the port 101 to the head ends of the hydraulic cylinder 48 and the reservoir 70 so that compressed air in the rod end of the cylinder 7 is transmitted through the tube 100 to the hydraulic cylinder 48 and through the port 101 to act on thepiston 78 in the reservoir 70. Thus, air admitted through the port 34 to retract the piston 24 also forces the hydraulic piston 46 downwardly, as viewed in Fig. 1, into its initial positions, thereby forcing the hydraulic fluid in cylinder 48 through port 92 into cylinder 11. Similarly, the compressed air admitted through the port 101 into the upper end of the secondary reservoir 70 drives the secondary reservoir piston 78 downwardly to force the hydraulic fluid held therein through the check valve 74 and the port 76 into the secondary cylinder 62. The returning fluid forces the secondary piston 64 downwardly to drive the outer anvil 56 back to its advanced position preparatory to a repetitive operation of the gun.

An oil reservoir 102 may also be provided within the drive tube 26 of the hydraulic ram assembly 12. The reserve oil in the reservoir 102 may be pressurized by a piston 104 biased forwardly by a spring 105. The oil may be fed into the cylinder 11 through a valve 106 provided in the ram piston 28. Such a supply minimizes difficulties that might otherwise be encountered in the event of leakage of hydraulic fluid during operation of the gun.

In order that the gun may be filled conveniently with hydraulic fluid, suitable fittings, such as 110 and 114, may be provided.

The hydraulic pressure at which secondary movement takes place, i. e., at which the outer anvil 56 is retracted, may be varied by adjusting the biasing spring 71 of the valve 68 through the agency" of a screw 69 in order to 'provide proper operation under varying conditions and with various types and sizes of rivets.

While a preferred embodiment of the invention has been shown and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.

What is claimed is:

1. In a fluid-actuated pull gun, the combination comprising a body defining first and second cylinders, a pair of pistons, one of said pistons mounted for reciprocation in each of the cylinders defined by said body, rod means fixed to one of said pistons, the longitudinal axis of said rod means being ofiset with respect to the longitudinal axis of the first cylinder,.means for successively establishing fluid circuits to the first cylinder at opposite ends of said one piston to drive said one piston in opposite directions, and means responsive to a predetermined fluid pressure in the first cylinder for permitting relative movementbetween said second piston means and said body.

2. In afluid-actuated pull gun, the combination comprising a body defining first and second cylinders, a first piston mounted for reciprocation in the first cylinder defined by said body, a second piston mounted for reciprocation in the second cylinder defined by said body, means for successively establishing fluid circuits to the firstcylinder at opposite ends of said first piston to drive said first piston in opposite directions, and mean responsive to the fluid pressure in the first cylinder for establishing .fiuid circuits communicating with the second cylinder.

piston mounted'for reciprocation in the first cylinder defined by said body, a rod .fixed to said first pist0n,.a

'second=piston mounted iforxreciprocationxin :the second cylinder define'd by said body, :the i longitudinal :gaxis of said rodbeing ofiset with respec't' to the. longitudinal :axis -ofithe first cylinder, means for successively establishing 'fiuid'circuits-to the first cy'linder at opposite ends'of said first piston todrive said first piston in opposite directions, "and means responsive to the fiuid pressure in the "first cylinder for establishing 'fluid' circuits communicating with the second cylinder.

4. In a fluid-actuated pull gunythe combination comprising a 'bodydefining first'and second cylinders, a first piston mounted for reciprocation in the first cylinder defined by said body, a second piston mounted'for reciprocation in the .second'cylin'der defined by said body, the longitudinal axis of said first piston being offset with respect to the longitudinal axis of said second piston, means including .valve means for successively establishingfluid circuits toth'ei'first cylinder at opposite ends of said first piston to .drive said first piston in opposite ,directions,.fluid reservoir means,'and meansrespons'ive to .t'he fluid pressure in the first cylinder ior establishing a vfluidpath between the second cylinderand said reservoir.

5. in afluid actuated pullgun, the combination comyprisingabody defining first andsecond cylinders, a first piston mounted for reciprocation -in the first cylinder defined byIsaid body, a rod fixed .tosaid .first' piston, a :second piston mounted in the second cylinder .for recipro- -cation relativeto-saidrod, thetlongitudinal axis ,of said rod being offset with trespectto the longitudinal axis-of said first piston, means including valve means for successively :establishing :fluid circuits zto zthe :first, cylinder at opposite endsofsaid firstpiston to .drive said first piston in opposite directions, and means responsive to the fluid pressure in the -fir-st cylinder for controlling the "fluid pressure in the secondtcylinder.

6. In a fluid-actuated pull gunythecombination com- --pi'ising a ib'o'dy .defining. firstiand second cylinders, :a;first piston mounted for reciprocation in the first cylinder defined by said body, a rod fixed to said first piston, a second piston mounted in the second cylinder for reciprocation relative to said rod, the longitudinal axis of said rod being offset with respect to the longitudinal axis of said first piston, the longitudinal axis of said rod being aligned with the longitudinal axis of said second piston, means including valve means for successively establishing fluid circuits to the first cylinder at opposite ends of said first piston to drive said first piston in opposite directions, and means responsive to the fluid pressure in the first cylinder for controlling the fluid pressure in the second cylinder.

7. In a fluid-actuated pull gun, the combination including a body defining a pair of spaced cylinders, a first piston mounted for reciprocation in one of the cylinders defined by said body, a second piston mounted for reciprocation in the other cylinder, means including first valve means selectively operable to successively establish fluid circuits to the one cylinder at opposite ends of said first piston to drive said first piston in opposite directions, and means for controlling the movement of said second piston in the other cylinder as a function of the fluid pressure in the one cylinder.

8. In a fluid-actuated pull gun, the combination including a body defining a pair of spaced cylinders, a first piston mounted for reciprocation in one of the cylinders defined by said body, a piston rod fixed to said first piston, the longitudinal axis of said rod being offset with respect to the longitudinal axis of said first piston, a second piston mounted for reciprocation in the other cylinder, means including first valve means selectively operable to successively establish fluid circuits to the one cylinder at opposite ends of said first piston to drive said first piston in opposite directions, and means including second valve means responsive to the fluid pressure in the.one cylinder for controlling the fluid "pressure and =the=movementof-the second piston in the other cylinder.

'9. In a fluid-actuated pull gun, the combination .:in-

cluding-chow defining apair of-spaced cylinders, vartist piston mounted for reciprocation in .one of the cylinders defined bysaid body, agpistonrodfixed to saidfirst piston,

the longitudinalaxisofsaid rod being ofiset with respect to'therlongitudinal axis of said'first piston, asecondpiston mountedfor reciprocation inthe other cylindenmeans including first valve means selectively operable to successively establish fluid circuits to the one cylinder at oppositeends of said first piston to drive said first piston .in opposite directions, means including second valve means responsiveto the fluid pressure .in'the one cylinder for controlling the fluid pressure and the movement of said second piston in the other cylinder, and :driving .means operatively connected to said pistons.

10. Ina fluid-actuatedpull gun, the combination comprising :a body defining a1pair of spaced icylinders, a'first .pistonvmounted for reciprocation in vone .of the cylinders definedby saidzbody, a second piston mounted for reciptrocation in .the other cylinder, a first fluid reservoir, first-fluid circuit means connecting said first fiuid'reservoir withitheone cylinderdefined'by said-body, a second fluid reservoir, second fluid circuit means connecting said second reservoir with the other of saidcylinders, selectively operable control -means for controlling the flow of fluidthrough said first circuit means, and means responsive .to the fluid pressure .in the first cylinder for controlling the flowof fluid through said second circuit means.

'11. .In..a fluid-actuatedpull gun, the combination comprisingarpair-of longitudinally spaced cylinders, arfirst pistonmounted for-reciprocation inone of the cylinders .defined by said body, a rod fixed'to said first piston with the longitudinal axis thereof oflset with respect to the longitudinal axis of said first piston, a .second v piston .mountedin the other cylinder for I movement relative to said rod,.rneans for forcing fluid-under pressure intotthe one cylinder, means responsive to the'fiuid pressure in the one cylinder for controlling the fluid pressure in the other cylinder, and successively actuable driving means operatively connected to said pistons.

12. In a fluid-actuated pull gun, the combination comprising a housing defining a bore, first piston means mounted for reciprocation in the bore defined by said housing, a body defining a pair of longitudinally spaced cylinders, second piston means mounted for reciprocation in one of the cylinders defined by said body, third piston means mounted for reciprocation in the other cylinder defined by said body, means including first valve means selectively operable to actuate said first piston means to force fluid under pressure into the one cylinder, and means including second valve means responsive to the fluid pressure in the one cylinder for controlling the fluid pressure in the other cylinder.

13. in a fluid-actuated pull gun, the combination comprising a housing defining a bore, first piston means mounted for reciprocation in the bore defined by said housing, a body defining a pair of longitudinally spaced cylinders, second piston means mounted for reciprocation in one of the cylinders defined by said body, a rod fixed to said second piston means with the longitudinal axis thereof offset with respect to the longitudinal axis of said second piston means, third piston means mounted in the other cylinder defined by said body for movement relative to said rod, means including first valve means selectively operable to actuate said first piston means to force fluid under pressure into the one cylinder, means including second valve means responsive to the fluid pressure in the one cylinder for controlling the fluid pressure in the other cylinder, and driving means operatively connected to said second and third piston means.

14. In a fluid-actuated pull gun, the combination comprising a housing defining a bore, a first piston mounted 'for reciprocation in the bore defined by saidhousing, a

-.'body defining a pair of longitudinally spaced cylinders, a

second piston mounted for reciprocation in one of the cylinders defined bysaidbody, a rod fixed to said second zpiston with the longitudinal axis thereof ofisetwith respect to the longitudinal axis of said second.;piston, a third piston mounted in the'other cylinderdefinedby said 'body formovement relative to said rod, means including first valve means selectively operable t actuate said first piston to force fluid under pressure into the one cylinder, means including second valve means responsive to the fluid pressure in the one cylinder for controlling the fluid pressure in the other cylinder, and driving means operatively connected to said second andthird pistons.

15. In a fluid actuated pull gun, the-combination comprising a body defining a cylinder having first and second sections, a first piston mounted for reciprocation in the first section of the cylinder defined by said body, a second piston mounted forreciprocation in-the second section of the cylinder defined by saidbody, means for successively' 'establishingfluid circuitsto thei-first section'of the cylinder at opposite ends of said first piston to drive said first piston in opposite directions, and means responsive to the fluid pressure in the first section of the cylinder for establishing fluid-circuits communicating with-the second section of the cylinder. I

16. In a fluid actuated pull gun, the combination-comprising a body defining a cylinder having first and second sections, a pair of pistons, one of said pistons mounted for reciprocation in each of the sections of the cylinder defined by said body, rod means fixed to one of said pistons, the longitudinal axis of said rod means being ofiset with respect to the longitudinal axis of the first section of the cylinder, means for successively establishing fluid circuits to the first section of the cylinder at opposite ends of said one piston to drive saidone piston in opposite directions, and means responsive to a predetermined fluid pressure in the first section of the cylinder for permitting relative movement between said second piston means and said body.

17. In aifluid actuated pull gun, the combination including a: bodydefining a cylinder having first and sec ondisections, a first piston mounted for reciprocation in the first: section of the cylinder; defined by said body, a

:secondpiston'mounted for reciprocation in the second second section of. the cylinder defined by said body, se-

lectively operable controlmeansfor controlling the flow ,of fluid through saidfirst circuit means, and means responsive to the fluid pressurefin the first section of the cylinder defined by said body' for controlling the flow of fluid through said second circuit means. 7

18. In a fluid actuated pull gun, the combination comprising a housing defining "a bore,, first piston means mounted for reciprocation in' the bore defined by said housing, a body defining a cylinder having a pair of sections, second piston means mounted for reciprocation in one section of the cylinder defined by said body, third piston means mounted for reciprocation in the other section of the cylinder defined by said body, means including first valve means selectively operable to actuate said first piston means to force fluid under pressure into the one section of the cylinder, and means including second 'valve means responsive to the fluid pressure in the one section of they cylinder for controlling the fluid pressure in the other section of the-cylinder.

References Cited inthe'file of this patent UNITED STATES PATENTS 2,526,956 Kugler Oct. 24, 1950 FOREIGN PATENTS I Great Britain-.9,- Dec. 30, 194.2 

